> ## Documentation Index
> Fetch the complete documentation index at: https://mux.coder.com/llms.txt
> Use this file to discover all available pages before exploring further.

# ACP (Editor Integrations)

> Connect Mux to Zed, Neovim, and JetBrains via the Agent Client Protocol

Mux implements the [Agent Client Protocol (ACP)](https://agentclientprotocol.org/) to integrate
with editors that support it. The `mux acp` command starts a stdio bridge that any
ACP-compatible editor can spawn as a subprocess.

<Info>
  ACP is the "LSP for agents" and provides session management, tool delegation, and streaming. Mux
  uses ACP (not MCP) for its editor bridge.
</Info>

## Zed

Zed has native ACP support and does not require a plugin.

Open **Settings** (`Cmd+,`) and add:

```json theme={null}
{
  "agent_servers": {
    "Mux": {
      "type": "custom",
      "command": "mux",
      "args": ["acp"]
    }
  }
}
```

<Accordion title="Using npx (no global install)">
  ```json theme={null}
  {
    "agent_servers": {
      "Mux": {
        "type": "custom",
        "command": "npx",
        "args": ["-y", "mux", "acp"]
      }
    }
  }
  ```
</Accordion>

### Connect to a remote server

Pass `--server-url` and `--auth-token` in `args`:

```json theme={null}
{
  "agent_servers": {
    "Mux": {
      "type": "custom",
      "command": "mux",
      "args": ["acp", "--server-url", "https://mux.example.com", "--auth-token", "<token>"]
    }
  }
}
```

Or set environment variables for any `mux acp` process:

```bash theme={null}
MUX_SERVER_URL=https://mux.example.com \
MUX_SERVER_AUTH_TOKEN=<token> \
mux acp
```

## Neovim

Two plugins currently support ACP in Neovim.

### codecompanion.nvim (recommended)

[codecompanion.nvim](https://github.com/olimorris/codecompanion.nvim) added ACP support in
v17.18. Add the adapter in your `lazy.nvim` config:

```lua theme={null}
require("codecompanion").setup({
  adapters = {
    mux = function()
      return require("codecompanion.adapters").extend("acp", {
        name = "mux",
        schema = {
          model = { default = "mux" },
        },
        args = { "mux", "acp" },
      })
    end,
  },
  strategies = {
    chat = { adapter = "mux" },
    inline = { adapter = "mux" },
  },
})
```

See the
[codecompanion ACP adapter docs](https://codecompanion.olimorris.dev/configuration/adapters-acp)
for full options.

### agentic.nvim

[agentic.nvim](https://github.com/carlos-algms/agentic.nvim) is a dedicated ACP client.
Requires Neovim 0.11 or newer. Add via `lazy.nvim`:

```lua theme={null}
{
  "carlos-algms/agentic.nvim",
  opts = {
    agents = {
      mux = {
        cmd = "mux",
        args = { "acp" },
      },
    },
  },
}
```

## JetBrains

JetBrains ACP support requires the **AI Assistant** plugin (2025.3 or newer).

1. Open the **AI Chat** tool window
2. Click **More** (`...`) then **Add Custom Agent**
3. Add the Mux entry to the `acp.json` that opens:

```json theme={null}
{
  "agent_servers": {
    "Mux": {
      "command": "mux",
      "args": ["acp"]
    }
  }
}
```

<Note>ACP is not supported in WSL-backed JetBrains projects.</Note>

See the [JetBrains ACP docs](https://www.jetbrains.com/help/ai-assistant/acp.html) for more
information.

## Flags and environment variables

| Flag                   | Environment variable    | Description                                                                |
| ---------------------- | ----------------------- | -------------------------------------------------------------------------- |
| `--server-url <url>`   | `MUX_SERVER_URL`        | URL of a running Mux server                                                |
| `--auth-token <token>` | `MUX_SERVER_AUTH_TOKEN` | Bearer token for authenticated connections                                 |
| `--log-file <path>`    | —                       | Write ACP logs to a file (useful when your editor hides subprocess stderr) |

<Warning>`MUX_AUTH_TOKEN` is not read by `mux acp`. Use `MUX_SERVER_AUTH_TOKEN`.</Warning>

If no `--server-url` is provided, `mux acp` first attempts to discover a running server via the
lockfile in `~/.mux/`, then starts an in-process server automatically when needed.

## Troubleshooting

* **Logs hidden by your editor:** use `--log-file /tmp/mux-acp.log` to capture ACP stderr output.
* **Connection refused:** ensure Mux is running (`mux server` or the desktop app), or omit
  `--server-url` to let ACP auto-start in-process.
* **Tool calls are not delegated:** the editor must advertise filesystem or terminal capabilities,
  and the workspace must use `local` runtime mode.

## Related

* [CLI Reference — `mux acp`](/reference/cli#mux-acp)
* [VS Code Extension](/integrations/vscode-extension)
* [Workspaces](/workspaces)